Screening apparatus and method for making

Abstract

An apparatus and method for fabricating a one or two-dimensional microassays with a matrix of sites favorably disposed for screening substances such as biomolecules, chemicals or cells as described. The method includes drilling a matrix of wells or through-holes in a glass or similar material using a laser. The drilling creates a region favorably disposed towards binding a molecule or cell. A microassay plate includes a substrate and at least one hole in the substrate containing an immobilized reactant bound to an interior surface of the hole. An array of holes having chemically different immobilized reactants is provided. Holes may be drilled using one or more pulses of light of extremely short duration to create a surface in a localized area that preferentially binds to material.

1 . A substrate for selectively attracting particles comprising: 
 a surface;    a particle attracting receptor adjacent to the surface; and    at least a portion of the receptor having a positive charge.    
     
     
         2 . The substrate of  claim 1  wherein the receptor is a through-hole.  
     
     
         3 . The substrate of  claim 1  wherein the receptor is a blind hole.  
     
     
         4 . The substrate of  claim 1  wherein the receptor comprises a peripheral wall extending above the surface.  
     
     
         5 . The substrate of  claim 1  wherein the receptor comprises a region on the surface of the substrate.  
     
     
         6 . The substrate of  claim 1  comprising a plurality of receptors.  
     
     
         7 . The substrate of  claim 1  in which the substrate comprises identification indicia.  
     
     
         8 . The substrate of  claim 7  wherein the identification indicia is formed by the same process that forms at least one receptor.  
     
     
         9 . The substrate of  claim 7  wherein the indicia comprises a bar code.  
     
     
         10 . The substrate of  claim 9  in which the bar code comprises a two dimensional bar code.  
     
     
         11 . The substrate of  claim 1  wherein the substrate comprises a glass.  
     
     
         12 . The substrate of  claim 1  in which the substrate comprises a semiconductor.  
     
     
         13 . The substrate of  claim 7  comprising identification indicia formed on the surface.  
     
     
         14 . The substrate of  claim 7  comprising indentification indicia formed in the substrate.  
     
     
         15 . The substrate of  claim 1  comprising a plurality of receptors arranged along a channel.  
     
     
         16 . The substrate of  claim 1  comprising a plurality of receptors arranged in an array.  
     
     
         17 . The substrate of  claim 1  in which the receptor comprises an immobilized reactant.  
     
     
         18 . The substrate of  claim 17  wherein the immobilized reactant comprises at least one molecule.  
     
     
         19 . The substrate of  claim 17  in which the immobilized reactant comprises at least one molecule that fluoresces upon excitation when attached to a specific particle.  
     
     
         20 . The substrate of  claim 17  wherein the reactant comprises a tag that absorbs light at a wavelength of excitation and emits light at a characteristic wavelength different from the wavelength of excitation.  
     
     
         21 . The substrate of  claim 1  wherein the surface comprises a reflecting surface.  
     
     
         22 . The substrate of  claim 21  wherein the reflecting surface reflects light at an excitation wavelength.  
     
     
         23 . The substrate of  claim 1  comprising a filter on the surface to filter out the excitation wavelength.  
     
     
         24 . The substrate of  claim 1  wherein the substrate comprises a colored glass.  
     
     
         25 . The substrate of  claim 23  wherein the filter comprises a coating on the surface.  
     
     
         26 . The substrate of  claim 1  in which at least a portion of the surface surrounding a receptor is hydrophobic or liquiphobic.  
     
     
         27 . The substrate of  claim 1  comprising a coating on at least a portion of the surface that is resistant to binding of an immobilized reactant.  
     
     
         28 . The substrate of  claim 27  in which the coating comprises alkane thiols or polyethylene glycol.  
     
     
         29 . The substrate of  claim 24  in which at least a portion of the surface surrounding the immobilized reactant comprises a hydrophobic or liquiphobic material.  
     
     
         30 . The substrate of  claim 24  comprising a coating on at least a portion of the surface surrounding the immobilized reactant that is resistant to binding of an immobilized reactant.  
     
     
         31 . The substrate of  claim 32  comprising a binding means for controlling the binding of a cell membrane to the receptor.  
     
     
         32 . The substrate of  claim 1 , wherein the particle attracting receptor comprises a cell attracting receptor.  
     
     
         33 . The substrate of  claim 1 , wherein the particle attracting receptor comprises at least one molecule attracting receptor.  
     
     
         34 . The substrate of  claim 33  comprising binding means for controlling the binding of at least one molecule to the receptor.  
     
     
         35 . The substrate of  claim 20  wherein the tag comprises a luminescent or radioactive tag.  
     
     
         36 . The substrate of  claim 20  wherein the tag comprises a luminescent tag and the tag emits at a luminescent wavelength.  
     
     
         37 . The substrate of  claim 20  in which the fluorescent tag is characterized by multiphoton absorption.  
     
     
         38 . The substrate of  claim 1  comprising at least one waveguide coupled to at least one receptor.  
     
     
         39 . The substrate of  claim 38  in which the waveguide is coupled to a surface other than the one to which the receptor is affixed.  
     
     
         40 . The substrate of  claim 38  wherein the waveguide optically connects the receptor to a surface other than the one on which the receptor is affixed.  
     
     
         41 . A method for fabricating a microassay plate comprising: directing at least one pulse of light having a pulse width less than 100 ps from a first laser to at least one localized area on the surface of the plate to form a receptor.  
     
     
         42 . The method of  claim 41  wherein directing at least one pulse of light comprises ablating a portion of the surface to create the receptor.  
     
     
         43 . The method of  claim 41  comprising heating the surface.  
     
     
         44 . The method of  claim 43  comprising melting and resolidifying at least a portion of the surface to form the receptor.  
     
     
         45 . The method of  claim 44 , the heating step comprising heating the surface with a burst of light pulses.  
     
     
         46 . The method of  claim 44 , comprising melting and resolidifying using a laser.  47 . The method of  claim 43 , in which the heating step comprises heating the surface to a temperature less than that required to form a plasma.  
     
     
         47 . The method of  claim 43 , in which the heating step comprises heating the substrate to a softening temperature that is below the melting temperature.  
     
     
         48 . The method of  claim 47 , in which the heating step comprises heating the surface with a laser.  
     
     
         49 . The method of  claim 41  comprising directing a beam of light pulses on the surface the pulses characterized by a pulse length sufficient to create positive ions, ablate the surface, and heat the surface adjacent to the ablated site to form a liquid layer.  
     
     
         50 . The method of  claim 41  comprising forming the receptors in a vacuum.  
     
     
         51 . The method of  claim 41  comprising forming the receptors in an atmosphere free of contaminants.  
     
     
         52 . The method of  claim 41  comprising packaging the assay in an environment free of contaminants.  
     
     
         53 . The method of  claim 41  comprising forming the receptors in the presence of an electric field.  
     
     
         54 . The method of  claim 41  comprising heating the micro assay plate to a temperature just below its melting point.  
     
     
         55 . The method of  claim 49  comprising preheating the micro assay plate.  
     
     
         56 . The method of  claim 41  comprising forming the receptors in a body of glass characterized by a characteristic filtering wavelength.  
     
     
         57 . The method of  claim 41  comprising coating the surface with a layer of filter material.  
     
     
         58 . The method of  claim 41  comprising coating the surface with a layer of a reflective material.  
     
     
         59 . The method of  claim 41  comprising writing waveguide in the plate.  
     
     
         60 . The method of  claim 59  comprising forming the waveguide and the receptor with a single laser.  
     
     
         61 . The method of  claim 41 ,comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         62 . The method of  claim 49  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         63 . The method of  claim 59  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         64 . The method of  claim 41  comprising a coating at least a portion of the surface with a material that is resistant to binding of an immobilized reactant prior to forming the receptor.  
     
     
         65 . The method of  claim 49  comprising a coating at least a portion of the surface with a material that is resistant to binding of an immobilized reactant prior to forming the receptor.  
     
     
         66 . The method of  claim 59  comprising a coating at least a portion of the surface with a material that is resistant to binding of an immobilized reactant prior to forming the receptor.  
     
     
         67 . The method of  claim 64  comprising coating the surface with alkane thiols or polyethylene glycol.  
     
     
         68 . A method of making a substrate favorably disposed towards holding a cell comprising: 
 providing a substrate having a surface;    directing at least one pulse of light having a pulse width less than 100 ps from a first laser to at least one localized area on the surface of the plate to form a receptor area, void, or hole characterized by an affinity for a cell.    
     
     
         69 . The method of  claim 68  wherein directing at least one pulse of light comprises ablating a portion of the surface.  
     
     
         70 . The method of  claim 68  comprising heating the surface during the step of directing a beam of less than 100 ps pulses of light on the surface of the substrate.  
     
     
         71 . The method of  claim 68  comprising melting and resolidifying at least a portion of the surface of the receptor.  
     
     
         72 . The method of  claim 68  comprising directing a beam of light pulses on the surface, the pulses characterized by a pulse length sufficient to create positive ions, ablate the surface, and heat the surface adjacent to the ablated site to form a liquid layer.  
     
     
         73 . The method of  claim 68  comprising heating the entire substrate to a temperature just below its melting point.  
     
     
         74 . The method of  claim 68  comprising forming the receptors in a body of material characterized by a characteristic filtering wavelength.  
     
     
         75 . The method of  claim 68  comprising coating a surface of the substrate with a layer of filter material.  
     
     
         76 . The method of  claim 68  comprising coating a surface of the substrate with a layer of a reflective material.  
     
     
         77 . The method of  claim 68  comprising writing at least one waveguide in the substrate.  
     
     
         78 . The method of  claim 74  comprising writing at least one waveguide in the body of the material.  
     
     
         79 . The method of  claim 68  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         80 . The method of  claim 72  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         81 . The method of  claim 77  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         82 . The method of  claim 79  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         83 . A method of creating an array of microstructures in a material for use in molecular sequencing comprising: 
 directing at least one pulse of light having a pulse width less than 100 ps. from a first laser to at least one localized area to form a receptor.    
     
     
         84 . The method of  claim 83  wherein directing at least one pulse of light comprises ablating a portion of the surface to form the receptor.  
     
     
         85 . The method of  claim 83  comprising heating the surface during the step of directing a beam of less than 100 ps pulses of light to the localized area.  
     
     
         86 . The method of  claim 83  comprising melting and resolidifying at least a portion of the substrate.  
     
     
         87 . The method of  claim 83  comprising directing a beam of light pulses on the surface characterized by a pulse length sufficient to create positive ions, ablate the surface, and heat the surface adjacent to the ablated site to form a liquid layer.  
     
     
         88 . The method of  claim 83  comprising heating at least a portion of the micro assay plate to a temperature just below its melting point when machining it with light pulses.  
     
     
         89 . The method of  claim 83  comprising forming a receptor in a material characterized by a characteristic filtering wavelength.  
     
     
         90 . The method of  claim 83  comprising coating a surface with a layer of filter material.  
     
     
         91 . The method of  claim 83  comprising coating a surface with a layer of a reflective material.  
     
     
         92 . The method of  claim 83  comprising writing waveguide channels in the material.  
     
     
         93 . The method of  claim 89  comprising writing at least one waveguide in the body of the material.  
     
     
         94 . The method of  claim 83  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         95 . The method of  claim 87  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         96 . The method of  claim 92  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         97 . The method of  claim 93  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         98 . A method of creating a receptor in a substrate for use cellular electrophysiology comprising: directing at least one pulse of light having a pulse width less than 100 ps. from a first laser to at least one localized area on the surface of the plate to form a cell receptor.  
     
     
         99 . The method of  claim 98  wherein directing at least one pulse of light comprises ablating a portion of the surface to create the cell receptor.  
     
     
         100 . The method of  claim 98  comprising heating the surface during the step of directing a beam of less than 100 ps pulses of light on the surface of the substrate.  
     
     
         101 . The method of  claim 98  comprising melting and resolidifying at least a portion of the surface of the receptor.  
     
     
         102 . The method of  claim 98  comprising directing a beam of light pulses on the surface characterized by a pulse length sufficient to create positive ions, ablate the surface, and heat the surface adjacent to the ablated site to form a liquid layer.  
     
     
         103 . The method of  claim 98  comprising heating at least a portion of the substrate to a temperature just below its melting point when directing the at least one pulse of light on the substrate.  
     
     
         104 . The method of  claim 98  in which the substrate comprises a body of glass characterized by a characteristic filtering wavelength.  
     
     
         105 . The method of  claim 98  comprising coating a surface of the substrate with a layer of filter material.  
     
     
         106 . The method of  claim 98  comprising coating a surface of the substrate with a layer of a reflective material.  
     
     
         107 . The method of  claim 98  comprising writing waveguide channels in the substrate.  
     
     
         108 . The method of  claim 98  comprising forming a receptor in a material characterized by a characteristic filtering wavelength.  
     
     
         109 . The method of  claim 98  comprising writing at least one waveguide in the body of the material.  
     
     
         110 . The method of  claim 108  comprising writing at least one waveguide in the body of the material.  
     
     
         111 . The method of  claim 98  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         112 . The method of  claim 108  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         113 . The method of  claim 109  comprising coating at least a portion of the surface with a hydrophobic or liquiphobic material prior to forming the receptor.  
     
     
         114 . The substrate of  claim 30  in which the coating comprises alkane thiols or polyethylene glycol.